Are the QS4 and QS8 brackets the same? Im thinking of ordering QS8 for my sides and moving my QS4s to the rear. If the brackets are off by a very small amount.that could be well too close holes problems with the drywall and cause some extra work on my part. If the connect points are an inch plus. I dont see a problem

yeah, i would think you could just take off the existing speakers and slide the new ones onto the same bracket. I would think they are the same (looking from a manufacturing stand point it would make sense)